1. Technical Field
This invention relates generally to an apparatus and method for removing a prosthetic hip cup from a pelvic bone, and more specifically to a tool having interchangeable heads for removing hip cups having different dimensions.
2. Background Art
Over the years, advances in medical procedures have helped countless people live normal lives after suffering devastating ailments. One such area of advancement has been in the field of orthopedic medicine, which is the curing of disorders of the musculoskeletal system. In particular, progress in the field hip replacement has been very important to helping those with mobility problems caused by hip damage.
One common type of hip ailment is the loss of cartilage in the hip sockets, which hold rotary balls attached to the femur bones. This relationship between the hip sockets and the rotary balls enables a person to walk and perform other movement of the legs. In a healthy hip, the cartilage present in the hip socket acts as a cushion that enables the rotary ball to move freely in the hip socket. As this cartilage deteriorates, sometimes with age and sometimes with disease, the rotary ball may begin to rub against the bone surface of the hip socket thereby causing bone on bone grinding. This grinding may be very painful.
To help people with damaged cartilage in their hips, doctors sometimes replace the rotary ball of the femur with a prosthetic rotary device, and insert a prosthetic hip cup into the pelvic bone. The prosthetic rotary device then fits within the prosthetic hip cup, and works as an artificial hip. Over time, these prosthetic pieces may become worn and may need to be replaced. Tools to replace the prosthetic hip cup are known in the art. The problem with these prior art replacement tools, however, is that they are typically designed for only one type or size of hip cup. For instance, they may be designed to work with only one manufacturer's cup or one size cup.
In recent years, new hip cup designs have been introduced. In general, these designs are made by different manufacturers and in different sizes. Because of their varying sizes, tools used to replace the specific hip cups are not suitable for use with these varying sized cup implants. For example, when a tool designed to remove the small hip cup is used to remove a larger hip cup, the tool may not seat properly within the cup, thereby making the cutting process erratic and haphazard.
There is thus a need for an improved hip cup removal device suitable for use with hip cups of varying sizes.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.